constructs an sf of MULTIPOLYGON objects
Usage
sf_multipolygon(
obj = NULL,
x = NULL,
y = NULL,
z = NULL,
m = NULL,
multipolygon_id = NULL,
polygon_id = NULL,
linestring_id = NULL,
close = TRUE,
keep = FALSE,
list_columns = NULL
)Arguments
- obj
sorted matrix or data.frame
- x
x geometry column
- y
y geometry column
- z
z geometry column
- m
m geometry column
- multipolygon_id
column of ids for multipolygons
- polygon_id
column of ids for polygons
- linestring_id
column of ids for lines (within polygons)
- close
logical indicating whether polygons should be closed. If
TRUE, all polygons will be checked and force closed if possible- keep
logical indicating if the non-geometry and non-id columns should be kept. if TRUE you must supply the geometry and id columns, and only the first row of each geometry is kept. See Keeping Properties.
- list_columns
vector of column names to turn into a list.
notes
sfheaders functions do not perform any validity checks on the geometries. Nor do they set Coordinate Reference Systems, EPSG, PROJ4 or precision attributes.
The data.frame and matrices you send into the sfheader functions must be ordered.
Keeping Properties
Setting keep = TRUE will retain any columns not specified as a
coordinate (x, y, z, m) or an id (e.g., linestring_id, polygon_id) of the input obj.
You can use list_columns to specify which of the properties will be turned into
a list, thus keeping all the values in the column. For columns not specified in list_columns,
only the first row of the column is kept
The sf_* functions assume the input obj is a long data.frame / matrix,
where any properties are repeated down the table for the same geometry.
Examples
m <- matrix(c(0,0,0,0,1,0,0,1,1,0,0,1,0,0,0), ncol = 3, byrow = TRUE )
sf_multipolygon( m )
#> id geometry
#> 1 1 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0
df <- data.frame(
id = c(1,1,1,1,1)
, x = c(0,0,1,1,0)
, y = c(0,1,1,0,0)
)
sf_multipolygon( df, x = "x", y = "y" )
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0
df <- data.frame(
id = c(1,1,1,1,1,2,2,2,2,2)
, x = c(0,0,1,1,0,1,1,2,2,1)
, y = c(0,1,1,0,0,1,2,2,1,1)
)
sf_multipolygon( df, multipolygon_id = "id", polygon_id = "id", linestring_id = "id")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0
#> 2 2 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
df <- data.frame(
id1 = c(1,1,1,1,1,1,1,1,1,1)
, id2 = c(1,1,1,1,1,2,2,2,2,2)
, x = c(0,0,1,1,0,1,1,2,2,1)
, y = c(0,1,1,0,0,1,2,2,1,1)
)
sf_multipolygon( df, multipolygon_id = "id1", polygon_id = "id2")
#> id1 geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
df <- data.frame(
id1 = c(1,1,1,1,1,1,1,1,1,1,2,2,2,2,2)
, id2 = c(1,1,1,1,1,2,2,2,2,2,1,1,1,1,1)
, x = c(0,0,1,1,0,1,1,2,2,1,3,3,4,4,3)
, y = c(0,1,1,0,0,1,2,2,1,1,3,4,4,3,3)
)
sf_multipolygon( df, multipolygon_id = "id1", polygon_id = "id2")
#> id1 geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
#> 2 2 3, 3, 4, 4, 3, 3, 4, 4, 3, 3
df <- data.frame(
id1 = c(1,1,1,1,1,2,2,2,2,2)
, id2 = c(1,1,1,1,1,1,1,1,1,1)
, x = c(0,0,1,1,0,1,1,2,2,1)
, y = c(0,1,1,0,0,1,2,2,1,1)
)
sf_multipolygon( df, multipolygon_id = "id1", polygon_id = "id2" )
#> id1 geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0
#> 2 2 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
sf_multipolygon( df, polygon_id = "id1", linestring_id = "id2" )
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
sf_multipolygon( df, x = "x", y = "y", polygon_id = "id1")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
sf_multipolygon( df, x = "x", y = "y", polygon_id = "id1", linestring_id = "id2")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
sf_multipolygon( df, x = "x", y = "y", linestring_id = "id1")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1
sf_multipolygon( df, x = "x", y = "y", linestring_id = "id2")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 1, 1, 2, 2, 1, 0, 0, 1, 1, 0, 0, 1, 2, 2, 1, 1, 0
df <- data.frame(
id1 = c('a','a','a','a','a','b','b','b','b','b')
, id2 = c(1,1,1,1,1,1,1,1,1,1)
, x = c(0,0,1,1,0,1,1,2,2,1)
, y = c(0,1,1,0,0,1,2,2,1,1)
)
sf_multipolygon( df, x = "x", y = "y", polygon_id = "id1")
#> id geometry
#> 1 1 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1